Shotgun Ammo Guide

How Gauge is Measured

Shotguns are among the most versatile firearms available. With that versatility, a vast and confusing market exists for ammunition. There are thousands of types of shotgun shells, all with different projectiles and powders to give you an edge in whatever task you and your trusty shotgun are trying to accomplish. If you are a beginner to the shotgun world, lets take a minute and figure out how in the heck we’re supposed to pick out the right ammo.


How Gauge is Measured
How Gauge is Measured

When shopping for shotgun ammo, the first step is to find the right gauge. The industry measures most shotguns in gauges instead of calibers. You would expect that 12 gauge means some sort of linear measurement, but it isn’t. A 12 gauge means that you can make 12 balls of equal size out of a pound of lead and they will each fit the diameter of the barrel precisely. This is why a 20 gauge is smaller than a 12. This originated when you made your own ammunition and you bought lead by the pound. A notable exception is the .410, which is a very small shotgun measured by its bore size. If we measured the .410 by gauge, it would be roughly equivalent to a 68 gauge.

Chamber Length

Once you have your gauge figured out, its time to look at inches. In the case of 12-gauge shotguns, chambers generally come in 2-¾, 3 and 3-½-inch chamber lengths. It is very important that you only fire shells that are the length of, or shorter than your corresponding chamber length. For instance, you can safely fire a 2-¾-inch shell out of a 3-½-inch chamber, but not the other way around. If the shell is too long, you will create too much chamber pressure and you could damage the firearm or more importantly, yourself. However, always check your firearm’s manual to make sure what length of shell it will take. If you don’t know, then just stick with the chamber length you know you have and there won’t be any worries.

Shot Size

Using the proper shot size is very important. You will be much more effective at the sport if you know your way around the various shot sizes. The larger the number, the smaller the individual pellets. Generally, the smaller the pellets, the more there are. For example, a No. 8 dove load will have tiny .09-inch pellets, while a No. 4 turkey load will have fewer pellets, but with .13-inch diameters. Buckshot follows a similar patter, meaning the higher the number, the smaller the individual pellets. No. 3 buckshot pellets measure 0.25 inches, while 00 or double-aught buckshot measures in at a huge 0.33-inch per pellet. For hunters, the following chart illustrates proper shot size for various game animals.

Game Lead/Tungsten Steel
Pheasant 4 to 6 2 to 3
Turkey 4 to 6 2 to 3
Quail, dove, 7-½ to 8
Rabbit 6 to 7-½
Squirrel 6
Geese BB to 2 TT to 1
Ducks, low 4 to 6 2 to 4
Ducks, high 2 to 4 BB to 2

Slugs and Sabots

A slug is usually a single projectile fired from a shotgun. It can either be dense and heavy for hunting and combat, or light and less lethal for law enforcement applications. Slugs also offer a way to hunt in areas that outlaw traditional rifle hunting. Most slugs are effective at ranges inside 100 yards, and their weight delivers a large amount of kinetic energy to the target. Newer saboted slugs are metallic projectiles supported by a plastic sabot, which engages the rifling in a rifled shotgun barrel and imparts a ballistic spin onto the projectile. This differentiates them from traditional slugs, which do not typically benefit from a rifled barrel.

Materials Used

Lead is still the most common material for shotgun pellets. However, at the beginning of the 21st century, ammo manufacturers began producing lead-free shotshell ammunition loaded with steel, bismuth or tungsten. The alternative materials are non-toxic and used in various types of hunting, especially waterfowl. If you have an older shotgun, stick with lead. The hardness of non-toxic materials can damage your firearm. Make sure you know your state’s hunting laws before using any type of lead or non-toxic material. Different areas have different requirements and you don’t want to break any hunting laws.

What is your favorite shotshell for hunting? For home defense? Tell us in the comment section.

The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (18)

  1. Home defense #1 buck. many years ago when only shotguns could be used for hunting deer in some of the southern states. The NRA funded several large studies for the best deer loads. The winner was #1 buck. I’ve taken a lot of deer with this load.

  2. Hey there
    Kauriking #4
    There are a number of sabot rounds that you may use effectively with no damage. Look for rounds that are encased in breakaway plastic. The shells I mentioned in my post above are excellent too for smooth bore.

    Regards, Pete

  3. Mark– Thanks alot for your advice on how to break in my new Taurus .22PT. It’s just disconcerting at first to have a brand new nickel-finish gun with rosewood grips go all crazy on you at the firing range. I am sure that during this breaking in period the main return spring on the slide will loosen up some. Like I said, it is way, way too powerful a spring right now. The spring in the magazine was way too tight at first also, but after just about 30 rounds, it loosened up. This is just a backup gun: I have a Very Reliable Taurus .38 Special for carry that takes .38 Special +P Hornady hollowpoints. Thanks again for your advice !!! –Donald.

  4. Don, I can speak from experience regarding this. Take it from me, use only HV ammo for the first 200 rounds or so (either CCI Stinger or Aguila HV) and this will allow for a good break-in. after that you can alternate for range use with SV and HV but I highly recommend HV only for SD purposes. BTW, this applies to any .22lr gun I have ever had from the short barrel PT22, Beretta 21A, Phoenix HP22A etc. all the way to the GSG 1911-22, Ruger SR22 etc…

  5. Looking for comments on Jamming with my brand new Taurus PT-22 (.22 LR, semi-auto).

    Most often jams with one round in the chamber and a full magazine. The casing from

    the first round will jam up against the freshly fed round from the magazine. Is any

    type of .22 LR ammunition better than any other for this problem ?

  6. I have a Remington 1100 smoothbore 12 gauge… could I use SABOT slugs or would it damage the barrel?

  7. Extremely interesting article (tons of great knowledge can be gleaned from the CTD Blogs). I have forever said that “arguably” the shotgun is the single best, affordable and versatile weapon the average man can have and is, perhaps, indispensable/must-have hardware. I say for someone looking to either take game, shoot recreationally at trap/skeet/competition and/or use for SD/HD either CQB with buckshot or long distance (100yds+) via slugs that for $190-300 you can get a great pump-action or for $399 up an outstanding semi-auto. Critics (honestly there are not too many) will maintain that capacity is the one (maybe only) downside but most people will not need more than a mag full #00 Buckshot or 1 1/4oz Slug and if so can easily reload (watch 3-Gun matches for example). I will, however, confess that I am a certified shotgun aficionado and understand the platform backwards/forward and find little to nothing in terms of potential disadvantages–that said I stand by my recommendation and have done so for close family members which allows me to sleep well at night ;). Just to reiterate, LOVE the CTD Blogs!

  8. I always wondered what kind of calculation/measurement was used to determine the various shotgun gauge numbers. Know I know, thank you very much for sharing that knowledge.

  9. I carry a 12 ga 870 where ever I go in Alaska. On the road, boat, plane, quad, horseback or hiking, its been a part of me since I was a kid. It may be the singular most Versatel firearm in Alaska. Before everyone jumps feet first on my head I would add that I carry a light fram 454 as a back up too. Most Alaskans have a shotgun, its one of our basic Bush tools. About the only time I don’t carry the 870 is when hunting as I’m then generally outfitted with a .300 WinMag, but the 870 is in camp.
    For the majority of my other outings and most notably fishing the 870 is always there, When it comes to ammunition I generally configure the magazine with rounds 1 & 2 as Monolit32 Balistic solid slugs. Rounds 3 & 4 are Hexolit32 expanding & splintering slugs. Rounds 5 & 6 are either #1 buck or a Buck and Ball loading. This loading is repeated in the spare round holder on the side of the recover. In addition I will often carry, in a vacuume sealed bag, three shot shells that are big enough for bird or small game 6 or 7 1/2 shot, 6 Marine Flare rounds and three Flash/Bang rounds. Bears and Moose are common and can be agressive. Generally a round fired in their direction will turn them away but on the rare occasions that they decide to push the envelope you need a load out such as described above.
    The Hexo/Mono, #1Buck & the Buck & Ball also make excellent home defense rounds. If your a big game shotgun hunter the Hexo & Mono series of shells by DDupleks ( are excellent choices in both smooth bore and rifled platforms. Accuracy is excellent, energy at impact is excellent, and they are lead free. I have only ever found them in 2 3/4″ but have taken a few apart and reloaded them into 3 and 3 1/2 inch shells there is no noticeable change in the fligh of the rounds in the longer case loading and accuracy seems unaffected. Bird and small game are not my normal quarry so I can’t say to much about those requirments and will leave that to far better informed shot gunners than myself. Although I have a very nice set of Bretta over-n-unders, in 20ga and 28 ga for those lower 48 western bird hunts I get occasion to go on.
    Choose your ammunition as carefully as you would the firearm you will use. Be very aware of your local hunting regs and what your state allows you to hunt with in the way of type and material of shot. Be safe out there!

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